Because the desire to be accepted is a central human motive, it is not surprising that rejection can trigger a variety of maladaptive reactions, including violence and depression. Nevertheless, there are individual differences in how people react to rejection. We have previously proposed that rejection sensitivity (RS) --the disposition to anxiously expect, readily perceive and intensely react to rejection -- helps explain this variability. Our research to date has shown that people who anxiously expect rejection more readily perceive it in others' behavior and then react in hostile ways that undermine their relationships. The purpose of the proposed research is to understand more fully why people who anxiously expect rejection behave in ways that lead to the realization of their worst fears. Our approach is guided by the view that RS develops to defend the self against rejection while maintaining social connection. We propose that situations where high RS individuals expect rejection activate the defensive motivational system (DMS), a generic system evolved to guide rapid and intense responses to threats of danger. DMS prepares the organism to detect threat-relevant cues, to engage in vigorous efforts to prevent the realization of the threat, and to react quickly and intensely if the threat is realized. This viewpoint leads to the following predictions about the dynamics of RS, which guide the specific aims of the application: Aim 1 is to test the assumption that RS is a defensively motivated system that gets elicited by rejection-relevant stimuli. We will do so by establishing whether in rejection-relevant contexts individuals high in RS show heightened potentiation of the startle response, a robust indicator of DMS activation. Aim 2 is to examine whether, when the DMS is activated by the possibility of rejection, high RS individuals show both a heightened propensity to detect interpersonal negativity and to interpret such negativity as personal rejection. In combination, these processes can potentially explain why HRS individuals more readily perceive rejection than those low in RS. Aim 3 is to test whether being in this defensive state triggers vigorous efforts to prevent rejection, that involve over-accommodation to partners through self-silencing and excessive solicitousness. We will also test whether over-accommodation gives way to hostile and dejected overreactions when rejection is perceived. [unreadable] [unreadable]